1. Field of the Invention
This invention relates to improvements in contacting means between a gas and a liquid in a wet scrubbing tower and more particularly relates to improvements in scrubbers for removing sulfur dioxide from a gas stream passing through the scrubber.
2. Discussion of the Prior Art
In the processing of waste gases containing particulate materials therein, as well as chemically reactive substances, it is a commonly accepted practice to remove these undesirable materials by passing the waste gas through a scrubbing tower. The scrubbing towers generally contain water or chemically reactive solutions therein to react with or absorb the undesirable materials in the gas stream as the gas passes through the scrubbing tower. Particularly in the case of the removal of oxides of sulfur from the burning of coal in utility plants and the like, in order to remove these undesirable oxides from the waste gas stream, many different types of scrubbing devices have been devised. In most cases chemical solutions containing alkaline or similar compounds which react with these oxides of sulfur to form soluble sulfites and sulfates have been proposed for use in scrubbing towers. The most commonly used scrubbing devices include complex baffle means within the scrubbing zone of the tower to promote liquid-gas contact or contact elements in the form of stationary or floating beds are used wherein the cleaning solution coats the elements and as the gas passes through the beds the oxides of sulfur come in contact with the scrubbing solution on the contact elements. However, in both types of the aforementioned devices large amounts of energy are used for forcing the gases through the devices as well as for pumping of the chemical reacting spraying solutions to spray nozzles in the scrubbing device. Furthermore, the design of these scrubbing devices have been found to be complex and quite expensive in order to obtain satisfactory removal of the oxides of sulfur from a waste gas stream.
Several devices are known in the prior art for scrubbing dirty gases utilizing troughs or baffles therein to form sheets of cleaning liquid through which a gas to be cleaned comes in contact. These include, for example, those described in U.S. Pat. Nos. 3,350,076; 3,656,279; 3,392,967; 3,895,926; 3,799,572; 3,550,356; and 3,533,608.